Preheat the oven to 375°F (190°C).
In a large bowl, combine the sliced mushrooms, chopped onion, minced garlic, thyme, rosemary, salt, and pepper.
Drizzle the olive oil over the mushroom mixture and toss to coat evenly.
In a baking dish, arrange the chicken breasts in a single layer. Pour the mushroom mixture over the chicken.
In a small bowl, mix the chicken broth and lemon juice, then pour it over the chicken and mushrooms.
Cover the baking dish with aluminum foil and bake for 25 minutes.
Remove the foil and bake for an additional 15-20 minutes, or until the chicken is cooked through (internal temperature should reach 165°F).
Remove from the oven and let it rest for 5 minutes before serving. Garnish with fresh parsley.